The assessment and diagnosis of abdominal pain in childhood continues to be a clinical challenge. We audited the presenting symptoms and signs in a consecutive series of 447 children presenting to a paediatric surgical unit in an attempt to quantify the value of particular symptoms and signs in differentiating acute appendicitis (AA) from non-specific abdominal pain (NSAP). The onset of pain in the centre of the abdomen and radiation of pain was not sufficient to differentiate between NSAP and AA. Progression of pain, nausea, vomiting, anorexia and diarrhoea were significantly more common in children with AA (P < 0.01). Similarly, facial flushing, tachycardia (pulse > 100 beats/min), guarding and rebound tenderness were significantly more common in children with AA (P < 0.001). Knowledge of this quantitative data could help clinicians adjust the weighting given to the presence of a particular symptom or sign in children with acute abdominal pain.